Striking teachers have highlighted the statistic that the Colombian government still spends more on war than education.

The largest teachers' union in Colombia launched a national strike Thursday to demand wage hikes and higher state investment in education across the country after failing to reach an agreement with the government of President Juan Manuel Santos.

Some 350,000 teachers from the Fecode union were expected to participate in the week-long schedule of job action and other events, including public open classes.

The union abandoned talks with the government after officials with the Ministry of Finance said the government didn't have a sufficient budget to settle the wage debts owed to teachers, saying, according to the union, that educators would have to wait until 2019 for the amounts owing to be paid. Wage disputes are only part of the unions broader demands for an increased national budget for education.

"We have not been able, for example, to reach agreements on the number of students that each teacher should have," said Carlos Rivas, president of Fecode to El Espectador. "While the logic is that each teacher has up to 15 students, we have 35 or 45. So we can only take care of them, but not teach them."

The teachers' union also called on parents and students to join the protest and demand investment in the education sector, saying that the country invests more money in war than education.

Santos argued that the teachers' union should remember that the country faces a fiscal tightening and that teacher's have already enjoyed higher salary increases since 2014 than other public sector workers, but refused to give in to the strike's demands.